First wash the lungs and heart and make a broth with water, vinegar, onions, bay leaves and cloves and simmer the giblets in it for about an hour.
Drain the lungs and heart (reserving the broth) and cut into fine pieces.
Melt the butter in a saucepan and stir in the flour until it turns a brown color.
Pour in the broth gradually until a creamy consistency is reached.
Add the lung and heart pieces to the sauce and simmer in it for about 20 minutes.
Season with salt, pepper, sugar and vinegar.